Phenolic resin compositions

ABSTRACT

Phenolic resin compositions comprising a polymeric substance having a phenolic OH group such as phenol resins, and a rubber having an epoxy group and an epoxy equivalent of 500 to 30,000 such as butadiene copolymers, acrylic copolymers, chloroprene copolymers and urethane copolymers are provided. These resin compositions exhibit improved properties having overcome the drawback of brittle properties intrinsic of conventional phenolic resins, and also exhibit cold resistance; hence they are used as molding materials, laminating materials, casting materials, binders, etc. Further, molding resin compositions having improved solvent-resistance and metal insert properties are provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending application Ser. No.130,277, filed Mar. 14, 1980 now U.S. Pat. No. 4,378,450.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to phenolic resin composition usable asmolding materials, laminating materials, paints and lacquers, adhesives,binders for shell molds, grindstones, brake linings, etc., castingmaterials, foaming agents, etc.

Further, the present invention relates to molding phenolic resincompositions.

2. Description of the Prior Art

Polymeric substances having a phenolic OH group, employable in thepresent invention, include phenolic resins, alkenylphenolic polymers,copolymers of alkenylphenols with other polymerizable monomers,polymeric substances derived from phenolic compounds and paraxylylenedihalides or paraxylylene dialkyl ethers, etc. Polymers having aphenolic OH group other than phenolic resins will be hereinafterabbreviated to phenolic polymers.

As is well known, phenolic resins include general-purpose novolak typephenolic resins, novolak type phenolic resins having a high content ofortho bond and resol type phenolic resins. As for these resins, afterheat treatment thereof (if necessary, a formaldehyde-generating compoundsuch as hexamethylenetetramine being added thereto prior to thetreatment), the resulting cured substances have been employed forvarious uses. Namely the resins have been widely used as moldingmaterials, laminating materials, paints and lacquers, adhesives, variousbinders for shell molds, grindstones, brake linings, etc., castingmaterials for ornamental goods, tools, tablewares, etc., foamingmaterials, etc., and are commercially valuable materials. They, however,have a drawback of being intrinsically brittle, which is a commonproblem to phenolic resins. Thus, for example, in case where they areemployed as molding materials, it has been difficult to produce moldedproducts having complicated shapes or molded products of large sizes,since cracks are liable to occur in the resulting molded products.

Further, phenolic resins have been employed for molded productscontaining inserts, such as gripping parts of metallic tablewares,knives, forks, etc. In this case, conventional phenolic resins have beeninferior in the metal insert properties, and particularly when moldedproducts are produced at low temperatures as in winter season, crackshave been liable to occur on the contact surface of metals with phenolicresins, resulting in low production yield.

Still further, when phenolic resins are employed for laminated sheets,they are inferior in cold punchability. Thus, punching of such laminatedsheets has been carried out by elevating their temperature up to about120° C. to soften them. In this case, however, when the temperature ofthe sheets is returned to ordinary temperatures after completion of theabove hot punching, expansion shrinkage occurs in the base; hence theresulting products have dimensional errors and also warp etc. Thus ithas been impossible to apply such sheets to the fields of electricalequipments requiring high performances.

Furthermore, even when phenolic resins are employed as various binders,for example, when they are employed as brake lining, etc., crack, break,etc. occur in the resulting brake materials, etc. Thus, it has beenimpossible to display full performances.

In addition to these various practical problems, the resins are veryweak in the thermal impact at cold-hot repetitions. Thus, moldingmaterials and laminating materials consisting of phenol resins have hada drawback that cracks readily occur through thermal impact at cold-hotrepetitions.

Next, phenolic polymers will be mentioned. As for methods of employingthe phenolic polymers, there are illustrated a method of adding aformaldehyde-generating compound such as hexamethylenetetramine theretoand subjecting the resulting mixture to heat treatment to obtain a curedproduct for use, and a method of mixing a phenolic polymer with an epoxyresin and further adding a curing accelerator for epoxy resins to theresulting mixture, followed by subjecting them to heat treatment toobtain a cured product for use. These cured products have a superiorheat resistance, and some of them have now been commercially employed.These materials, however, also have a drawback of brittleness. Thus,when they are applied to molding materials, laminating materials, paintsand lacquers, adhesives, various binders such as shell molds,grindstones, brake linings, etc., casting materials for e.g. ornamentalgoods, tools, tablewares, etc., foaming materials, etc., they have haddrawbacks common to those of phenolic resins.

Heretofore, various studies have been made for overcoming theabove-mentioned various drawbacks of phenolic resins, and variousmethods have been proposed. Among them, methods of modifying phenolicresins with rubbers have been widely carried out. For example there is amethod wherein e.g. a novolak type phenolic resin is blended e.g. byroll kneading with a nitrile rubber consisting of units of acrylonitrileand butadiene, as a rubber having a relatively good compatibility, toprepare a resin having a nitrile rubber dispersed in a novolak typephenolic resin, and this resin is employed. Further, U.S. Pat. No.3,536,783 discloses a rubber-modified novolak type phenolic resinprepared by uniformly dispersing a novolak type phenolic resin in alatex of nitrile rubber consisting of units of acrylonitrile andbutadiene.

It is observed that the above-mentioned two problems, i.e. prevention ofthe resins from crack occurrence when the resins are employed as moldingmaterials and punchability of laminated sheets prepared employing theresins have been improved by the above-mentioned methods of the priorart, but other various problems have not yet been solved as mentionedbelow.

Particularly, when molding materials, laminating materials, brakematerials, etc. prepared employing the above-mentioned rubber-modifiedphenolic resins are employed under a condition of cold temperature,particularly -30° C. or lower, the effectiveness due to therubber-modification is lost and cracks are very liable to occur.

As for the crack occurrence caused by thermal impact through cold-hotrepetitions, product having a sufficiently high impact resistance hasnot yet been obtained. For example, the problem is raised when they areemployed in districts where temperature difference is large between dayand night, or when they are employed at places subjected to repeatedthermal impacts.

Further, the molding materials prepared employing the above-mentionednitrile rubber are insufficient in the oil resistance and solventresistance. For example when the molding materials are employed atplaces where they are always brought into contact with machine oils,solvents, etc., they are accompanied with fading of the surface of themolding materials and increase in the weight, and also reduction in theperformances is notable.

Still further, in the finishing step of the molding materials wheredegreasing with trichloroethylene or the like is often carried out,trichloroethylene resistance is inferior, the surface condition is alsoinferior, particularly fading occurs, resulting in reduction of thequality of the molded products thus obtained.

Furthermore, for improving the metal insert properties of phenolicresins, an attempt of employing nitrile rubbers together with phenolicresins has been made. However, although the metal insert properties havebeen considerably improved according to the method, a practical problemhas been raised because of its inferior solvent resistance. Namely,metal-inserted, molded products usually have oils, fats and fatty oilsattached thereto, and for removing them, degreasing step of immersingthem in a solvent such as trichloroethylene is indispensable. However,in the case of the molded products obtained according to theabove-mentioned method, fading or color unevenness occurs afterimmersion in trichloroethylene. Thus, values as commodities have beennotably reduced. When molding materials, laminating materials ofphenolic resins obtained employing the above-mentioned nitrile rubbersare applied to certain uses such as electric parts to be subjected to along time thermal hysteresis, a great deal of reduction in the physicalproperties occurs. Thus they have been restricted in their uses.

SUMMARY OF THE INVENTION

An object of the present invention is to provide phenolic resincomposition which have an improved cold resistance; do not readily causecracks even when subjected to thermal impact of cold-hot repetitions;have superior oil resistance, gasoline resistance and solventresistance; and have been improved in their intrinsic drawback ofbrittleness.

Another object of the present invention is to provide molding materialsand laminating materials being small in the deterioration of physicalproperties even when subjected to long time thermal hysteresis.

A still other object of the present invention is to provide phenolicresin compositions for molding being improved in the metal insertproperties and solvent resistance.

A further object of the present invention is to provide moldingmaterials which cause neither fading nor color unevenness even afterimmersion in trichloroethylene, in addition to the above-mentionedimprovement in the metal insert properties.

Other objects of the present invention will be apparent from thedescription mentioned below.

In accordance with the present invention, phenolic resin compositionscomprising a polymeric substance having a phenolic OH group and a rubberhaving an epoxy group and an epoxy equivalent of 500 to 30,000 isprovided.

BRIEF DESCRIPTION OF THE DRAWING

The drawing illustrates a relationship between Barcol hardness ofmolding materials of Example and Comparative example and temperatures,wherein curve 1 shows a relationship between Barcol hardness in Example44 and temperatures and curve 2 shows a relationship between Barcolhardness in Comparative Example 22 and temperatures.

DETAILED DESCRIPTION OF THE INVENTION

Polymeric substances having a phenolic OH group, employed in the presentinvention include phenolic resins and phenolic polymers.

Phenolic resins are obtained by reacting phenolic compounds withaldehydes in a conventional manner. As for phenolic compounds, phenol,cresols, xylenols, alkylphenols having C₁ -C₂₀ alkyl group such asethylphenol, propylphenol, butylphenol, amylphenol, octylphenol,nonylphenol, dodecylphenol, and phenols having a structure similar tothose of alkylphenols such as bisphenol A, phenylphenol, cumylphenol,styrenized phenol, alkenylphenols such as p-vinylphenol,o-isopropenylphenol, m-isopropenylphenol, p-isopropenylphenol, etc. areillustrated. Further, as for aldehyde components, aqueous solution offormaldehyde, paraformaldehyde, trioxymethylene, hexamethylenetetramine,other aliphatic aldehydes, and substituted or unsubstituted aromaticaldehydes are illustrated.

As for phenolic resins, there are known novolak type phenolic resinobtained by reacting the above-mentioned phenolic compounds withformaldehyde or the like in the presence of an acidic catalyst such ashydrochloric acid, sulfuric acid, oxalic acid, p-toluenesulfonic acid,phosphoric acid, in a molar ratio of aldehyde components to phenoliccompound components of 0.6 to 0.95; novolak type phenolic resins havinga high content of ortho bond, obtained by reacting phenolic compoundcomponents with aldehyde components in the presence of a catalyst,divalent metal halides, divalent metal hydroxides (such as magnesiumhydroxide, calcium hydroxide), divalent metal oxides (such as magnesiumoxide, cadmium oxide) or organic acid salts of divalent metals (such asmagnesium acetate, zinc acetate) (pH being made 2 to 4 in the case ofthe latter three catalysts), in a molar ratio of aldehyde components tophenolic compound components of 0.6 to 0.95; and resol type phenolicresins obtained by reacting phenolic compound components with aldehydecomponents in the presence of a basic catalyst such as caustic alkalies,ammonia or amines, in a molar ratio of aldehyde components to phenoliccompound components of 0.7 to 3.0.

Next, phenolic polymers include alkenylphenolic polymers such aspolyvinylphenol, polyisopropenylphenol, copolymers of alkenylphenolswith other polymerizable monomers such as styrene, α-methylstyrene,acrylonitrile, vinyl chloride, acrylic acid esters, methacrylic acidesters, maleic anhydride or vinyl esters of various other organic acids,and polymeric substances disclosed in British Pat. No. 1,150,203 toAlbright & Wilson Ltd. and commercially available as a tradename ofXylok (derived from phenolic compounds and paraxylylene dihalides suchas paraxylylene dichloride or paraxylylene dialkyl ethers such asparaxylylene glycoldimethyl ether,

Rubbers having an epoxy group referred to herein mean polymers having anepoxy equivalent of 500 to 30,000 and a glass transition temperature of25° C. or lower; they exhibit a viscous liquid state or a semisolidstate at room temperature; and their preferable glass transitiontemperatures are 0° C. or lower.

As for the rubbers, for example the following are employed:

acrylic copolymers having an epoxy group in their molecule; butadienecopolymers containing 50% by weight or more of butadiene units andhaving an epoxy group in their molecule; chloroprene copolymers havingan epoxy group in their molecule (these three copolymers will bereferred to collectively as rubber A); and urethane copolymers having anepoxy group in their molecule (which will be hereinafter referred to asrubber B).

Rubbers A refer to polymers obtained by subjecting a monomer having anunsaturated bond and an epoxy group in its molecule (hereinafterreferred to as monomer A) such as glycydyl acrylate, glycydylmethacrylate, allyl glycidyl ether, and at least one kind of otherpolymerizable monomers to bulk polymerization, emulsion polymerization,suspension polymerization or solution polymerization on the presence ofa conventional radical initiator.

As for the polymerizable monomers employable in the present invention,aromatic vinyl compounds such as styrene, vinyltoluene, vinylxylene,chlorostyrene, bromostyrene, dichlorostyrene, α-methylstyrene,acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid,acrylic acid esters such as methyl acrylate, ethyl acrylate, propylacrylate, butyl acrylate, hexyl acrylate, 2-hydroxyethyl acrylate,2-hydroxypropyl acrylate, 2-ethylhexyl acrylate, methacrylic acid esterssuch as methyl methacrylate, ethyl methacrylate, propyl methacrylate,butyl methacrylate, hexyl methacrylate, lauryl methacrylate,2-ethylhexyl methacrylate, acrylamide, methacrylamide, isoprene,butadiene, chloroprene, maleic anhydride, etc. are mentioned.

As for the radical initiators employable in the present invention,organic peroxides such as benzoyl peroxide, di-t-butyl peroxide, t-butylperbenzoate, cumene hydroperoxide, methyl ethyl ketone peroxide, organicazo catalysts such as 2,2'-azobisisobutyronitrile,2,2'-azobis(2,4-dimethylvaleronitrile),2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile),1,1'-azobiscyclohexanone-1-carbonitrile,2,2'-azobis(2-amidinopropane)hydrochloride, inorganic peroxides such aspotassium persulfate, ammonium persulfate, potassium bromate, hydrogenperoxide, redox catalysts wherein peroxides and reducing agents such asferrous sulfate are employed at the same time, etc. are mentioned.

The polymerization is carried out in a conventional manner ofpolymerization such as bulk polymerization, emulsion polymerization,suspension polymerization, solution polymerization, at a polymerizationtemperature of 0° C. to 150° C. and under the atmospheric pressure or anelevated pressure. In this case, chain transfer agents such as dodecylmercaptan, lauryl mercaptan may be at the same time employed asmolecular weight modifier.

Preferable combinations of polymerizable monomers of main two-componentsystem and main three-component system for preparing the above-mentionedrubbers A are shown in the following Table 1:

Table 1 Combination of two-component system

Monomer A--ethyl acrylate

Monomer A--propyl acrylate

Monomer A--butyl acrylate

Monomer A--hexyl acrylate

Monomer A--butyl methacrylate

Monomer A--hexyl methacrylate

Monomer A--chloroprene

Combination of three-component system

Monomer A--ethyl acrylate--acrylonitrile

Monomer A--propyl acrylate--acrylonitrile

Monomer A--butyl acrylate--acrylonitrile

Monomer A--hexyl acrylate--acrylonitrile

Monomer A--lauryl methacrylate--acrylonitrile

Monomer A--2-ethylhexyl acrylate--acrylonitrile

Monomer A--butadiene--styrene

Monomer A--butadiene--acrylonitrile.

In accordance with the combinations of polymerizable monomers shown inTable 1, it is possible to prepare rubbers A by introducing an epoxygroup into the molecule of acrylic copolymers, butadiene copolymerscontaining 50% by weight or more of butadiene units, chloroprenecopolymers, etc. The content of epoxy group in rubbers A has noparticular limitation, but in order that the effectiveness of thepresent invention is exhibited most, the content is usually preferred tobe about 500 to 30,000 in terms of epoxy equivalent. This rangecorresponds to about 0.5 to 30% by weight in case where glycidylmethacrylate is employed as raw material. In addition, the epoxyequivalent referred to herein means an equivalent weight per one epoxygroup (g/equiv).

Next, rubbers B are prepared in the following manner: In the firstplace, preparation of starting raw material will be mentioned.Polyoxyalkyleneglycols such as polyoxyethyleneglycol,polyoxypropyleneglycol, polyoxypropylenepolyoxyethyleneglycol,polyoxybutylene glycol, adipic acid type polyesterglycols obtained fromadipic acid and diethylene glycol or the like, or polyesterglycolsobtained from ε-caprolactone or the like, etc. are reacted with2,4-tolylene diisocyanate, diphenylmethane diisocyanate, naphthylenediisocyanate, diphenylsulfone diisocyanate or the like to prepare aprepolymer having isocyanate group at its terminal.

As for the above-mentioned polyoxyalkyleneglycols, adipic acid typepolyesterglycols and polyesterglycols, those of a hydroxyl equivalent of100 to 2,000 are employable, and as for the isocyanate equivalent ofprepolymer obtained by reaction with isocyanates, those of 500 to 6,000are preferable.

As for the preparation of rubbers B by the use of prepolymer havingisocyanate group at its terminal, the following two methods arementioned:

a method of reacting the above-mentioned prepolymer with a compoundhaving an epoxy group and a hydroxyl group in its molecule, such asglycidol, and a method of reacting the prepolymer with a compound havinga hydroxyl group and a double bond in its molecule (hereinafterabbreviated to monomer B) such as hydroxyethyl acrylate, hydroxyethylmethacrylate, to prepare a urethane rubber having a double bond at itsterminal, which rubber is then polymerized in the presence of monomer Aand a polymerizable monomer.

In the case of the former method, glycidol is added to the prepolymer sothat the amount of hydroxyl group in glycidol is 1.0 to 1.5 equivalentper one NCO equivalent, followed by reaction at a temperature of 50° to100° C. In this case, a conventional catalyst such as tert-amines,tetraalkyldiamines, aminoalcohols, dialkyltin compounds may be alsoemployed. Further, a solvent capable of dissolving prepolymer andglycidol together, such as ethyl acetate, methyl ethyl ketone, xylene,toluene may be also employed, if necessary. As for the reaction, it ispossible to regard the point when 90% or more of NCO group has reactedwith hydroxyl group in glycidol, as the end point of the reaction.

The epoxy equivalent of rubbers B thus prepared is in the range of 500to 6,000.

In the case of the latter method, a monomer B is added to the prepolymerso that the amount of hydroxyl group is 1.0 to 1.5 equivalent per oneNCO equivalent, followed by reaction at a temperature of 50° C. to 100°C. In this case, conventional catalyst and solvent may be employed, ifnecessary. As for the reaction, it is possible to regard the point when90% or more of NCO group has reacted with hydroxyl group in the monomerB, as the end point of the reaction. A urethane rubber thus obtained,having an unsaturated double bond in the terminal of the molecule isreacted with a monomer A, and if necessary, in the presence of apolymerizable monomer, and in the presence of a radical initiator toobtain an epoxy-containing urethane rubber.

In this case, as for the polymerizable monomers employable at the sametime with the monomer A and the urethane rubber having an unsaturateddouble bond in the terminal of the molecule, the following arementioned:

aromatic vinyl monomers such as styrene, vinyltoluene, vinylxylene,chlorostyrene, bromostyrene, dichlorostyrene, α-methylstyrene,acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid,acrylic acid esters such as methylacrylate, ethyl acrylate,propylacrylate, butylacrylate, hexylacrylate, methacrylic acid esterssuch as methyl methacrylate, ethyl methacrylate, propyl methacrylate,butyl methacrylate, hexyl methacrylate, etc.

One kind or more of them may be employed. Rubbers B can be prepared bybulk polymerization or solution polymerization, employing theabove-mentioned monomer A, urethane rubber having an unsaturated groupat the terminal of the polymer, and if necessary, one kind or more ofpolymerizable monomers. In this case, the same kind of radicalinitiators as employed in the preparation of rubbers A may be employed,and the polymerization temperature is preferably in the range of roomtemperature to 100° C. Further, the amounts of monomers A and urethanerubbers having an unsaturated group at the terminal of the molecule,employable in this case are preferably 0.5 to 30% by weight and 10 to90% by weight, respectively. The epoxy equivalent of the rubbers B thusprepared is in the range of 500 to 30,000.

Rubbers A and B having an epoxy group are mixed in solid state as it is,latex state or solution state, in an amount of 1 to 100 parts by weight,preferably 2 to 60 parts by weight, more preferably 2 to 30 parts byweight, in terms of the amount of solid matters calculated from those ofthe epoxy group-containing rubbers, with 100 parts by weight of apolymeric substance having a phenolic OH group. For example, when metalinsert properties are referred to with this respect, if theabove-mentioned amount is less than 1 part by weight, the effectivenessupon metal insert properties is poor, while if it exceeds 100 parts byweight, mixing at the time of melt-mixing is difficult, resulting in aproblem of processability.

The epoxy group-containing rubbers, after added to a polymeric substancehaving a phenolic OH group, are melt-mixed at a temperature of roomtemperature to 250° C.

The process for producing the phenolic resin compositions of the presentinvention will be mentioned in more detail.

If the rubbers having an epoxy group are employed without any solvent,novolak type phenolic resins or phenolic polymers may be convenientlymixed in molten state. In this case, kneading by means of e.g. rolls iseffective. Further, in the case of the mixing or kneading it is morepreferable to heat them for reducing their viscosity, if necessary.

Further, in case where the rubbers having an epoxy group are employed inthe form of latex or suspension, mere mixing of the both may besufficient in the case of resol type phenolic resins, but in some cases,the latex or suspension is preferably stabilized in the presence ofsurfactants or the like. Further, in case where they are applied tonovolak type phenolic resins or phenolic polymers, they may bemelt-mixed while dehydrated on heating after mixing, or the latex orsuspension may be added to the above-mentioned resins on heating andthey are melt-mixed under dehydration.

Further, in case where the rubbers having an epoxy group are employed inthe form of solution, if the solvent employed is a common solvent tothose for phenolic resins, e.g. ethyl acetate, the solution may be, asit is, added to resol type phenolic resins, but if the solvent is not acommon one, the solvent may be removed under reduced pressure, followedby replacement by a suitable solvent such as methanol, ethanol, acetone,etc. Further, in case where they are applied to novolak type phenolicresins or phenolic polymers, if the solvent employed is a common one tothose for the above-mentioned resins, they may be applied in the form ofsolution as it is, to the resins, or they may be applied also in theform of solid after removal of solvent. Further, in the case of beinginsoluble in the above-mentioned resins, the solution of the rubbershaving an epoxy group may be successively added to the resins on heatingand they may be melt-mixed while the solvent is removed.

In the above-mentioned phenolic resin compositions, epoxy group may notbe always reacted with phenolic OH group, but, in some cases, reactionof epoxy group with phenolic OH group may be promoted by heating oremploying a conventional curing accelerator for epoxy resins such asboron trifluoride-amine complexes, 5-member heterocyclic amines,6-member heterocyclic amines, tertiary amines, tertiary amine salts. Inthis case, the amount of curing accelerator added is preferably 0 to 5parts by weight based on 100 parts by weight of the phenolic resincompositions.

To the phenolic resin compositions obtained by the melt-mixing polymericsubstances having a phenolic OH group with epoxy group-containingrubbers are added a curing agent such as hexamethylenetetramine and ifnecessary, a curing auxiliary, a filler, a pigment, etc., followed bykneading at a roll temperature of 80° to 170° C., milling into moldingpowder and compression molding, transfer molding or injection molding ata temperature of 140° to 250° C. to obtain molded products.

The present invention has such an advantage that by optionally selectingepoxy group-containing rubbers, it is possible to optionally producerelatively rigid materials to flexible materials. Further, in the caseof conventional cured products of rubber-modified phenolic resins withnitrile rubbers, a portion of the rubbers are dissolved out when theproducts are extracted with solvents, whereas in the case of curedproducts of the phenolic resin compositions of the present invention,epoxy group-containing rubbers are not dissolved out even when theproducts are extracted with solvents. This fact is one of the specificfeatures of the present invention as never seen in the prior art, andconstitutes the reason of the superior solvent resistance of theproducts of the present invention. In the case of the present invention,the epoxy group-containing rubbers are not only present in the curedproducts in a reacted state, but also present in a uniformly particulatestate, and there is observed no intramolecularly plasticized phenomenoncaused by the fact that a portion of rubbers is dissolved and present inthe cured products as seen in the case of conventional rubber-modifiedphenolic resins.

Thus, low-temperature impact characteristic properties are notablyimproved, and also the proportion of reduction in the high-temperaturesurface hardness is far less than those of conventional products. Thisresults in a great advantage when the compositions of the presentinvention are employed as binders for brake lining, etc. Namely, whenconventional rubber-modified phenolic resins are employed,high-temperature hardness reduction has been so large that a problem inpractical use has been raised, whereas according to the presentinvention, such a drawback has been overcome to be able to employ thecompositions of the present invention as binders for brake lining, etc.

As for the resin compositions of the present invention, aformaldehyde-generating compound such as hexamethylenetetramine may beemployed as a curing agent, if necessary, and it is also possible tofurther add fillers such as calcium carbonate, clay, talc, silica,aluminum oxide, antimony trioxide and reinforcing agent, e.g. mineralfibers such as glass fiber, asbestos fiber or synthetic fibers such aspolyvinyl alcohol fiber, nylon fiber, etc. Further, it is also possibleto dissolve the phenolic resin compositions in a solvent and immerse inthe resulting solution, various substrates such as glass cloth, glassmat, asbestos paper, synthetic fiber mat, paper, cotton cloth, etc.,followed by removing the solvent to prepare a dry prepreg.

Further it is also possible to dissolve the phenolic resin compositionsin various organic solvents such as alcohol solvents e.g. methylalcohol, ethyl alcohol, butyl alcohol, octyl alcohol, 2-ethylhexylalcohol, nonyl alcohol, etc., ketone solvents e.g. acetone,methylethylketone, methyl isobutyl ketone, isophorone, etc., ethersolvents e.g. isopropylether, n-butyl ether, ethylene glycolmonomethylether, ethyleneglycol monoethyl glycol, etc., ester solventse.g. ethylacetate, isobutyl acetate, n-butyl acetate, 2-ethylhexylacetate, etc., aromatic solvents e.g. toluene, xylene, cyclohexane,ethylbenzene, etc. or solvent mixtures of the foregoing to therebyprepare varnishes, and if necessary to modify them with tung oil,linseed oil, epoxy resin, furan resin, cumarone resin or the like, tothereby make use of the resulting products as resins for paints andlacquers.

Still further, it is also possible to make use of the phenolic resincompositions comprising resol type phenolic resins as high temperatureor room temperature adhesives, in the aqueous solution state such assuspension state, latex state or in the solution state, employing asuitable curing agent such as acidic substance e.g. benzenesulfonicacid, toluenesulfonic acid, phenosulfonic acid, phosphoric acid,chloroalkylsulfonic acid, hydrochloric acid, sulfuric acid, oxalic acid,etc.

Furthermore, it is also possible to make use of the phenolic resincompositions comprising phenolic polymers as it is, as adhesives, andfurther utilize them as high temperature adhesives, employing epoxyresins and curing accelerators for epoxy resins at the same time.

Further it is possible to make use of the phenolic resin compositions asvarious binders such as shell molds, grindstones, brake linings, etc.,by blending hexamethylenetetramine to the compositions, well kneadingthe resulting blend by means of hot rolls or the like and finely millingthe resulting material into a particle size of 200 meshes or larger toprepare a powdery resin.

Further it is possible to make use of the phenolic resin compositionscomprising resol type phenolic resins as various binders such as shellmolds, grindstones, brake linings, etc., in the form of liquid resin asit is.

Further it is possible to make use of the phenolic resin compositions ascasting resins, by casting them and if necessary, a mixture thereofcomprising a curing agent such as hexamethylenetetramine, curingaccelerator, filler, pigment, etc., into various casting frames.

Further it is possible to make use of the phenolic resin compositions asfoamed products, by subjecting the compositions to heat treatment,employing a foaming agent such as dinitropentamethylenetetramine,azodicarbonamide, etc. and if necessary, in the presence of a curingagent such as hexamethylenetetramine.

As mentioned above, the phenolic resin compositions of the presentinvention can be widely used as molding materials, laminating materials,paints and lacquers, adhesives, various binders such as shell molds,grindstones, brake linings, casting materials for ornamental goods,tools, tablewares, foaming agents, etc., and are commercially valuablematerials.

Next, representative examples of the epoxy group-containing rubbersemployed in the present invention and then Examples of the phenolicresin compositions of the present invention will be mentioned, but thepresent invention is not to be construed as limiting the scope of thepresent invention.

[I] PREPARATION EXAMPLES OF EPOXY GROUP-CONTAINING RUBBERS Preparationexamples of butadiene copolymers 1. Preparation of rubber (1)

    ______________________________________                                        Butadiene          62     parts by weight                                     Acrylonitrile      35     parts by weight                                     Glycidyl methacrylate                                                                            3      parts by weight                                     n-Dodecyl mercaptan                                                                              1      parts by weight                                     Potassium persulfate                                                                             0.5    parts by weight                                     Anionic surfactant 5      parts by weight                                     Water              200    parts by weight                                     ______________________________________                                    

The above-mentioned materials having the above-mentioned constitutingproportion were subjected to polymerization in an autoclave at 30° C.for 20 hours to obtain a rubber (1). The content of solid matters inthis rubber was 30% by weight, and after drying in vacuo at atemperature of 50° C. or lower, the epoxy equivalent of the resultingrubber (1) was about 4,900.

2. Preparation of rubber (2)

    ______________________________________                                        Butadiene          64     parts by weight                                     Styrene            30     parts by weight                                     Glycidyl methacrylate                                                                            6      parts by weight                                     n-Dodecyl mercaptan                                                                              3      parts by weight                                     Potassium persulfate                                                                             0.5    parts by weight                                     Anionic surfactant 5      parts by weight                                     Water              200    parts by weight                                     ______________________________________                                    

The above-mentioned materials having the above-mentioned constitutingproportion were subjected to polymerization in an autoclave at 30° C.for 20 hours to obtain a rubber (2). The content of solid matters inthis rubber was 30% by weight, and after drying in vacuo at atemperature of 50° C. or lower, the epoxy equivalent of the resultingrubber (2) was about 2,400.

Preparation examples of acrylic copolymer rubbers 3. Preparation ofrubber solution (3)

    ______________________________________                                        Butyl acrylate     67     parts by weight                                     Acrylonitrile      30     parts by weight                                     Glycidyl methacrylate                                                                            3      parts by weight                                     Ethyl acetate      100    parts by weight                                     Azobisisobutyronitrile                                                                           1      parts by weight                                     ______________________________________                                    

The above-mentioned materials having the above-mentioned constitutingproportion were subjected to polymerization under the atmosphericpressure, under reflux of ethyl acetate for 3 hours, followed by furtheradding 1 part by weight of azobisisobutyronitrile, and furtherpolymerization under reflux of ethyl acetate for 3 hours to obtain arubber solution (3). The content of solid matters in the rubber solution(3) was 49% by weight, and after removal of the solvent, the epoxyequivalent of the resulting rubber (3) was about 4,900.

4. Preparation of rubber (4)

    ______________________________________                                        Butyl acrylate     64     parts by weight                                     Acrylonitrile      30     parts by weight                                     Glycidyl acrylate  6      parts by weight                                     Ethyl acetate      100    parts by weight                                     Azobisisobutyronitrile                                                                           1      parts by weight                                     ______________________________________                                    

The above-mentioned materials having the above-mentioned constitutingproportion were subjected to polymerization under the atmosphericpressure, under reflux of ethyl acetate for 3 hours, followed byremoving unreacted monomers and solvent to obtain a rubber (4). Theepoxy equivalent of this rubber (4) was about 2,500.

5. Preparation of rubber solution (5)

    ______________________________________                                        Ethyl acetate      50     parts by weight                                     Butyl acrylate     97     parts by weight                                     Glycidyl methacrylate                                                                            3      parts by weight                                     Ethyl acetate      50     parts by weight                                     2,2'-AzobIs-(2,4-  1      part by weight                                      dimethylvaleronitrile                                                         ______________________________________                                    

Among the above-mentioned materials, the first-mentioned ethyl acetatewas firstly fed, and a mixture of the other materials was successivelyadded under the atmospheric pressure, under reflux of ethyl acetate for5 hours, to effect polymerization, followed by further adding 0.5 partby weight of 2,2'-azobis-(2,4-dimethylvaleronitrile), and polymerizationunder reflux of ethyl acetate for 3 hours to obtain a rubber solution(5). The content of solid matters in the rubber solution (5) was 49% byweight, and after removal of the solvent, the epoxy equivalent of therubber (5) was about 4,900.

6. Preparation of rubber (6)

    ______________________________________                                        Ethyl acetate       50    parts by weight                                     Butyl acrylate      72    parts by weight                                     Butyl methacrylate  5     parts by weight                                     Acrylonitrile       20    parts by weight                                     Glycidyl methacrylate                                                                             3     parts by weight                                     2-2'-Azobis(2,4-dimethyl-                                                                         1     parts by weight                                     valeronitrile)                                                                Ethyl acetate       50    parts by weight                                     ______________________________________                                    

Among the above-mentioned materials, the first-mentioned ethyl acetatewas firstly added, and a mixture of the other materials was successivelyadded under the atmospheric pressure, under reflux of ethyl acetate for5 hours, to effect polymerization, followed by further adding 1 part byweight of 2,2'-azobis(2,4-dimethylvaleronitrile), and polymerizationunder reflux of ethyl acetate for 3 hours and thereafter removingunreacted monomers and solvent to obtain a rubber (6). The epoxyequivalent of the rubber (6) was about 4,900.

Preparation examples of chloroprene copolymer rubber 7. Preparation ofrubber solution (7)

    ______________________________________                                        Chloroprene        94     parts by weight                                     Glycidyl methacrylate                                                                            3      parts by weight                                     Styrene            3      parts by weight                                     Benzene            350    parts by weight                                     n-Dodecyl mercaptan                                                                              3      parts by weight                                     Benzoyl peroxide   1.5    parts by weight                                     ______________________________________                                    

The above-mentioned materials having the above-mentioned constitutingproportion were subjected to polymerization in an autoclave atpolymerization temperature of 60° to 80° C. for 6 hours to obtain arubber solution (7). The content of solid matters in the rubber solution(7) was about 22% by weight, and after removal of solvent, the epoxyequivalent of the rubber (7) was about 4,900.

8. Preparation of rubber solution (8)

    ______________________________________                                        Chloroprene        94     parts by weight                                     Glycidyl methacrylate                                                                            6      parts by weight                                     Benzene            350    parts by weight                                     n-Dodecyl mercaptan                                                                              3      parts by weight                                     Benzoyl peroxide   1.5    parts by weight                                     ______________________________________                                    

The above-mentioned materials having the above-mentioned constitutingproportion were subjected to polymerization in an autoclave atpolymerization temperatures of 60° to 80° C. for 6 hours to obtain arubber solution (8). The content of solid matters in the rubber solution(8) was about 22% by weight, and after removal of solvent, the epoxyequivalent of the rubber (8) was about 2,400.

Preparation examples of urethane polymer rubbers 9. Preparation ofrubber solution (9)

2,4-Tolylenediisocyanate (174 g) and dibutyltin dilaurate (0.01 g) wereadded to 2,000 g of polyoxypropylene glycol having an OH equivalent of2,000, to effect reaction at 70° C. for 5 hours and thereby, obtain aprepolymer having a NCO equivalent of about 2,150. Hydroxyethyl acrylate(122 g) was added thereto, followed by reaction at 70° C. for 7 hours toobtain a polymer having an unsaturation equivalent of about 2,300. To 60parts by weight of the polymer thus obtained were added 40 parts byweight of ethyl acetate, followed by elevating the temperature to 80° C.Thereafter a mixture of

    ______________________________________                                        Butyl acrylate  37     parts by weight                                        Glycidyl methacrylate                                                                         3      parts by weight                                        n-Dodecyl mercaptan                                                                           7      parts by weight                                                                            and                                       Azobisisobutyronitrile                                                                        1      parts by weight                                        ______________________________________                                    

was added over 8 hours to effect polymerization. After completion of theaddition, the resulting material was further maintained at 80° C. for 2hours. The content of solid matters in the resulting rubber solution (9)was about 70% by weight, and after removal of solvent, the epoxyequivalent of the rubber (9) was about 4,900.

10. Preparation of rubber (10)

2,4-Tolylenediisocyanate (87 g) and dibutyltin dilaurate (0.01 g) wereadded to 1,000 g of polyoxypropylenepolyoxyethylene glycol having an OHequivalent of 2,000, to effect reaction at 70° C. for 5 hours andthereby obtain a prepolymer having a NCO equivalent of 2,150. To thisprepolymer were added 39 g of glycidol to effect reaction at 70° C. for7 hours and thereby obtain a rubber (10) having an epoxy equivalent of2,200.

[II] PRODUCTION EXAMPLES OF PHENOLIC RESIN COMPOSITIONS EXAMPLE 1

A general-purpose novolak type phenolic resin prepared in the presenceof hydrochloric acid catalyst and having a softening point of 92° to 98°C. (Novolak #2000, tradename of a product manufactured by MitsuiToatsuChemicals, Japan) was employed as the general-purpose novolak typephenolic resin for the present invention. Namely, 150 g of theabove-mentioned rubber (1) were added to 500 g of the Novolak #2000, andwater was distilled off by vacuum drying and removed to the outside ofthe system. The resulting material was melt-mixed at 160° C. for 60minutes with stirring to obtain a phenolic resin composition 1.

EXAMPLE 2

In the same manner as in Example 1, 150 g of the above-mentioned rubbersolution (3) were added to 500 g of Novolak #2000, and the solvent wasdistilled off by vacuum drying and removed to the outside of the system.The resulting material was melt-mixed at 160° C. for 60 minutes withstirring to obtain a phenolic resin composition 2.

EXAMPLE 3

In the same manner as in Example 1, 50 g of the above-mentioned rubber(4) were added to 500 g of Novolak #2000, and the resulting material wasmelt-mixed at 180° C. for 60 minutes with stirring to obtain a phenolicresin composition 3.

Any of the phenolic resin compositions obtained above, together withother materials according to the following blending formulation werekneaded by means of heated rolls at 110° C. for 3 minutes, and thenmilled to prepare molding powder:

    ______________________________________                                        Phenolic resin composition                                                                        100    parts by weight                                    Hexamethylenetetramine                                                                            12     parts by weight                                    Wood flour          100    parts by weight                                    Magnesium stearate  1      parts by weight                                    Carbon black        5      parts by weight                                    ______________________________________                                    

For comparison, a case where a usual rubber containing no epoxy groupwas employed and a case where Novolak #2000 alone was employed, arementioned below as Comparative Examples 1 and 2.

COMPARATIVE EXAMPLE 1

The same composition as that employed in preparation of theabove-mentioned rubber (1) except that no glycidyl methacrylate wasemployed, was subjected to polymerization under the same conditions asthose employed in preparation of the rubber (1), to obtain a rubberlatex (C-1).

Next, 500 g of Novolak #2000 and 150 g of rubber latex (C-1) obtainedabove were melt-mixed under the same conditions as in Example 1 toobtain a phenolic resin composition, from which molding powder was thenprepared according to the above-mentioned formulation.

COMPARATIVE EXAMPLE 2

Novolak #2000 together with other materials according to the followingblending formulation were kneaded by means of heated rolls at 110° C.for 3 minutes and then milled to prepare molding powder:

    ______________________________________                                        Novolak #2000      100    parts by weight                                     Hexamethylenetetramine                                                                           12     parts by weight                                     Wood flour         100    parts by weight                                     Magnesium stearate 1      parts by weight                                     Carbon black       5      parts by weight                                     ______________________________________                                    

The respective molding powders obtained above were molded under theconditions of 170° C., 5 minutes and 100 Kg/cm², and the respectivecharacteristic values of the resulting molded products were observedaccording to the testing methods shown below. The results are shown inTable 2.

(1) Metal insert properties

Employing a metal test piece of brass having 30 mm in diameter and 5 mmthick, a metal insert molded product of 50 mm in diameter and 10 mmthick was prepared so that the metal piece was located at the centralpart and yet on the back surface of the molded product. This moldedproduct was then maintained in an oven at 120° C. for 60 minutes andthereafter maintained in dry ice-methanol at -40° C. for 60 minutes.Condition of cracks which occurred in the molded product obtained abovewas observed by judgement by means of naked eyes.

(2) Solvent resistance

A molded product of 50 mm in diameter and 10 mm thick was immersed intrichloroethylene for 30 minutes, and then the surface of the resultingproduct was observed. The results were classified into the followingranks for evaluation:

    ______________________________________                                        (i)    The surface condition was almost unchanged.                                                             A                                            (ii)   The surface faded somewhat.                                                                             B                                            (iii)  Fading and color unevenness of the                                                                      C                                                   surface were each to a medium extent.                                  (iv)   Fading and color unevenness of the surface                                                              D                                                   were each to a large extent.                                           ______________________________________                                    

                  TABLE 2                                                         ______________________________________                                                      Metal insert                                                                              Solvent                                                           properties  resistance                                          ______________________________________                                        Present invention                                                                             Among 5 test pieces,                                          Molded product  all of the five,                                                                            A                                               according to    no crack                                                      Example 1                                                                     Molded product  all of the five,                                                                            A                                               according to    no crack                                                      Example 2                                                                     Molded product  all of the five,                                                                            A                                               according to    no crack                                                      Example 3                                                                     Comparative examples                                                                          Among 5 test pieces,                                          Molded product  one had crack D                                               according to Com-                                                             parative ex. 1                                                                Molded product  all of the five                                                                             A                                               according to Com-                                                                             had crack                                                     parative ex. 2                                                                ______________________________________                                    

EXAMPLE 4

As in Example 1, 100 g of the above-mentioned rubber (2) were added to500 g of Novolak #2000, and water was distilled off by vacuum drying andremoved to the outside of the system. The resulting material wasmelt-mixed at 160° C. for 60 minutes with stirring to obtain a phenolicresin composition 4.

EXAMPLE 5

As in Example 1, 50 g of the above-mentioned rubber solution (5) wereadded to 500 g of Novolak #2000, and solvent was distilled off by vacuumdrying and removed to the outside of the system. The resulting materialwas melt-mixed at 160° C. for 60 minutes with stirring to obtain aphenolic resin composition 5.

EXAMPLE 6

As in Example 1, 100 g of the above-mentioned rubber solution (5) wereadded to 500 g of Novolak #2000, and solvent was distilled off by vacuumdrying and removed to the outside of the system. The resulting materialwas melt-mixed at 160° C. for 60 minutes with stirring to obtain aphenolic resin composition 6.

EXAMPLE 7

As in Example 1, 200 g of the above-mentioned rubber solution (5) wereadded to 500 g of Novolak #2000, and solvent was distilled off by vacuumdrying and removed to the outside of the system. The resulting materialwas melt-kneaded by means of heated rolls at 160° C. for 15 minutes toobtain a phenolic resin composition 7.

EXAMPLE 8

As in Example 1, 50 g of the above-mentioned rubber (6) were added to500 g of Novolak #2000, and the resulting material was melt-mixed at160° C. for 90 minutes with stirring to obtain a phenolic resincomposition 8.

EXAMPLE 9

As in Example 1, 100 g of the above-mentioned rubber (6) were added to500 g of Novolak #2000, and the resulting material was melt-kneaded bymeans of heated rolls at 160° C. for 15 minutes to obtain a phenolicresin composition 9.

EXAMPLE 10

As in Example 1, 150 g of the above-mentioned rubber solution (7) wereadded to 500 g of Novolak #2000, and solvent was distilled off by vacuumdrying and removed to the outside of the system. The resulting materialwas melt-kneaded by means of heated rolls at 160° C. for 15 minutes toobtain a phenolic resin composition 10.

EXAMPLE 11

As in Example 1, 150 g of the above-mentioned rubber solution (8) wereadded to 500 g of Novolak #2000, and solvent was distilled off by vacuumdrying and removed to the outside of the system. The resulting materialwas melt-kneaded by means of heated rolls at 160° C. for 15 minutes toobtain a phenolic resin composition 11.

EXAMPLE 12

As in Example 1, 70 g of the above-mentioned rubber solution (9) wereadded to 500 g of Novolak #2000, and solvent was distilled off by vacuumdrying and removed to the outside of the system. The resulting materialwas melt-kneaded by means of heated rolls at 160° C. for 15 minutes toobtain a phenolic resin composition 12.

EXAMPLE 13

As in Example 1, 140 g of the above-mentioned rubber solution (9) wereadded to 500 g of Novolak #2000, and solvent was distilled off by vacuumdrying and removed to the outside of the system. The resulting materialwas melt-kneaded by means of heated rolls at 160° C. for 15 minutes toobtain a phenolic resin composition 13.

EXAMPLE 14

As in Example 1, 50 g of the above-mentioned rubber (10) were added to500 g of Novolak #2000, and the resulting material was melt-kneaded bymeans of heated rolls at 160° C. for 15 minutes to obtain a phenolicresin composition 14.

EXAMPLE 15

A novolak type phenolic resin having a molar ratio ofphenol/formaldehyde of 0.75, a content of ortho bond as high as about75% and a softening point of 88° to 95° C. (Novolak #9000, tradename ofa product manufactured by Mitsui Toatsu Chemicals, Japan) was employed.

Namely, 100 g of the above-mentioned rubber latex (2) were added to 500g of the above-mentioned Novolak #9000, and water was distilled off byvacuum drying and removed to the outside of the system. The resultingmaterial was melt-kneaded by means of heated rolls at 160° C. for 15minutes to obtain a phenolic resin composition 15.

EXAMPLE 16

The above-mentioned rubber solution (3) (100 g) was added to 500 g ofthe above-mentioned Novolak #9000, and solvent was distilled off byvacuum drying and removed to the outside of the system. The resultingmaterial was melt-mixed at 160° C. for 60 minutes with stirring toobtain a phenolic resin composition 16.

EXAMPLE 17

The above-mentioned rubber solution (8) (150 g) was added to 500 g ofthe above-mentioned Novolak #9000, and solvent was distilled off byvacuum drying and removed to the outside of the system. The resultingmaterial was melt-kneaded by means of heated rolls at 160° C. for 15minutes to obtain a phenolic resin composition 17.

EXAMPLE 18

The above-mentioned rubber solution (9) (70 g) was added to 500 g of theabove-mentioned Novolak #9000, and solvent was distilled off by vacuumdrying and removed to the outside of the system. The resulting materialwas melt-kneaded by means of heated rolls at 160° C. for 15 minutes toobtain a phenolic resin composition 18.

Any of the phenolic resin compositions obtained above, together withother materials according to the following blending formulation werekneaded by means of heated rolls at 110° C. for 3 minutes, and thenmilled to prepare molding powder:

    ______________________________________                                        Phenolic resin composition                                                                        100    parts by weight                                    Hexamethylenetetramine                                                                            12     parts by weight                                    Wood flour          100    parts by weight                                    Magnesium stearate  1      parts by weight                                    Carbon black        5      parts by weight                                    ______________________________________                                    

For comparison, materials of the same compositions as those employed inpreparation of the above-mentioned rubbers, rubber latexes and rubbersolutions except that monomers having an unsaturated bond and an epoxygroup in their molecule (abbreviated to monomer A) were not used, wereprepared under the same conditions as in preparation of theabove-mentioned rubbers, rubber latexes and rubber solutions, and thesematerials are referred to as C-1 to C-9, respectively.

For example, C-3 refers to a material prepared employing the samecomposition as that employed in preparation of the above-mentionedrubber solution (3) except that no glycidyl methacrylate was employed,and under the same conditions as in preparation of the rubber solution(3).

C-10 refers to a material prepared employing the same composition asthat employed in preparation of the above-mentioned rubber (10) exceptthat n-propyl alcohol was employed in place of glycidol, and under thesame conditions as in preparation of the rubber (10).

COMPARATIVE EXAMPLE 3

A phenolic resin composition was prepared in the same manner as inExample 4 except that rubber latex C-2 was employed.

COMPARATIVE EXAMPLE 4

A phenolic resin composition was prepared in the same manner as inExample 5 except that rubber solution C-5 was employed.

COMPARATIVE EXAMPLE 5

A phenolic resin composition was prepared in the same manner as inExample 6 except that rubber solution C-5 was employed.

COMPARATIVE EXAMPLE 6

A phenolic resin composition was prepared in the same manner as inExample 7 except that rubber solution C-5 was employed.

COMPARATIVE EXAMPLE 7

A phenolic resin composition was prepared in the same manner as inExample 8 except that rubber C-6 was employed.

COMPARATIVE EXAMPLE 8

A phenolic resin composition was prepared in the same manner as inExample 9 except that rubber C-6 was employed.

COMPARATIVE EXAMPLE 9

A phenolic resin composition was prepared in the same manner as inExample 10 except that rubber solution C-7 was employed.

COMPARATIVE EXAMPLE 10

A phenolic resin composition was prepared in the same manner as inExample 11 except that rubber solution C-8 was employed.

COMPARATIVE EXAMPLE 11

A phenolic resin composition was prepared in the same manner as inExample 12 except that rubber solution C-9 was employed.

COMPARATIVE EXAMPLE 12

A phenolic resin composition was prepared in the same manner as inExample 13 except that rubber solution C-9 was employed.

COMPARATIVE EXAMPLE 13

A phenolic resin composition was prepared in the same manner as inExample 14 except that rubber C-10 was employed.

COMPARATIVE EXAMPLE 14

A phenolic resin composition was prepared in the same manner as inExample 15 except that rubber latex C-2 was employed.

COMPARATIVE EXAMPLE 15

A phenolic resin composition was prepared in the same manner as inExample 16 except that rubber solution C-3 was employed.

COMPARATIVE EXAMPLE 16

A phenolic resin composition was prepared in the same manner as inExample 17 except that rubber solution C-8 was employed.

COMPARATIVE EXAMPLE 17

A phenolic resin composition was prepared in the same manner as inExample 18 except that rubber solution C-9 was employed.

Any of the phenolic resin compositions of Comparative Examples 3 to 17,together with other materials according to the following formulationwere kneaded by means of heated rolls at 110° C. for 3 minutes, and thenmilled to prepare molding powder:

    ______________________________________                                        Phenolic resin composition                                                                        100    parts by weight                                    Hexamethylenetetramine                                                                            12     parts by weight                                    Wood flour          100    parts by weight                                    Magnesium stearate  1      parts by weight                                    Carbon black        5      parts by weight                                    ______________________________________                                    

(1) Solvent resistance

Molding powders obtained according to the above-mentioned Examples andComparative examples were molded under the conditions of 170° C., 5minutes and 100 Kg/cm², and the resulting molded products were milledinto a particle size of 100 meshes or larger, and extracted with varioussolvents, by means of Soxhlet's extractor, under reflux for 10 hours toacquire percentages extraction. The results are shown in Table 3.

As seen from Table 3, when rubbers having an epoxy group are employed,the resulting phenolic resin compositions are superior in the solventresistance as compared with those in case where rubbers having no epoxygroup are employed.

                  TABLE 3                                                         ______________________________________                                                    Percentage extraction*                                                        Trichloro-                                                                    ethylene     Acetone  Xylene                                      Molding Powder                                                                            (%)          (%)      (%)                                         ______________________________________                                        Example 4   0.20         0.24     0.28                                        Example 5   0.22         0.21     0.18                                        Example 6   0.34         0.38     0.35                                        Example 7   0.70         0.78     0.74                                        Example 8   0.40         0.42     0.40                                        Example 9   0.72         0.76     0.73                                        Example 10  0.30         0.26     0.32                                        Example 11  0.20         0.18     0.21                                        Example 12  0.28         0.32     0.30                                        Example 13  0.71         0.78     0.70                                        Example 14  0.18         0.20     0.15                                        Example 15  0.24         0.27     0.31                                        Example 16  0.38         0.40     0.33                                        Example 17  0.18         0.20     0.18                                        Example 18  0.40         0.42     0.35                                        Compara. ex. 3                                                                            3.0          2.8      2.9                                         Compara. ex. 4                                                                            2.2          2.2      2.2                                         Compara. ex. 5                                                                            4.3          4.2      4.1                                         Compara. ex. 6                                                                            7.9          7.7      7.8                                         Compara. ex. 7                                                                            4.2          4.2      4.2                                         Compara. ex. 8                                                                            7.8          7.5      7.6                                         Compara. ex. 9                                                                            2.9          2.8      2.9                                         Compara. ex. 10                                                                           2.9          2.8      2.9                                         Compara. ex. 11                                                                           4.2          4.2      4.2                                         Compara. ex. 12                                                                           7.6          7.4      7.5                                         Compara. ex. 13                                                                           4.2          4.0      4.1                                         Compara. ex. 14                                                                           3.0          2.9      3.0                                         Compara. ex. 15                                                                           4.1          4.0      4.1                                         Compara. ex. 16                                                                           2.9          2.8      2.9                                         Compara. ex. 17                                                                           4.1          4.1      4.1                                         ______________________________________                                         *Molding powder (10 g) was extracted with 100 g of solvent, and percentag     extraction was calculated from the difference between the original weight     and that after extraction of the powder.                                 

(2) Metal insert properties

Employing a metal test piece of cast iron having a regularly hexagonalshape of 29 mm in side and 13 mm thick and also having a cylindricalhollow part of 20 mm in diameter at its central part, a metal insertmolded product of 50 mm in diameter and 30 mm thick was prepared so thatthe metal piece was located at the central part and yet on the backsurface of the molded product.

The metal insert molded product was subjected to a hot-cold test whereinone cycle consisted of retention at 180° C. for 30 minutes andsubsequent retention at -40° C. for 40 minutes, and crack which occurredat the boundary between the metal part and the cured resin part wasobserved by naked eyes. The metal insert properties were expressed bythe number of cycle at which crack occurred. The results are shown inTable 4.

According to this test, it is indicated that the more the number ofcycle, the superior the metal insert properties of the material.

As seen from Table 4, products having rubbers containing an epoxy groupare superior in the metal insert properties to those having rubberscontaining no epoxy group.

                  TABLE 4                                                         ______________________________________                                                      Metal insert properties,                                                      member of cycle at which crack                                  Molded product                                                                              occured                                                         ______________________________________                                        Example 4*.sup.1     27    times                                              Example 6*.sup.1     52    times                                              Example 7*.sup.1     47    times                                              Example 8*.sup.1     42    times                                              Example 12*.sup.1    34    times                                              Example 15*.sup.2    24    times                                              Example 16*.sup.2    32    times                                              Example 17*.sup.2    22    times                                              Example 18*.sup.2    33    times                                              Compara. ex. 2*.sup.1                                                                              2     times                                              Compara. ex. 3*.sup.1                                                                              20    times                                              Compara. ex. 5*.sup.1                                                                              38    times                                              Compara. ex. 6*.sup.1                                                                              37    times                                              Compara. ex. 7*.sup.1                                                                              33    times                                              Compara. ex. 11*.sup.1                                                                             23    times                                              Compara. ex. 14*.sup.2                                                                             13    times                                              Compara. ex. 15*.sup.2                                                                             22    times                                              Compara. ex. 16*.sup.2                                                                             12    times                                              Compara. ex. 17*.sup.2                                                                             24    times                                              ______________________________________                                         *.sup.1 Molding conditions: 170° C., 5 minutes, 100 Kg/cm.sup.2        *.sup.2 Molding conditions: 160° C., 5 minutes, 100 Kg/cm.sup.2   

EXAMPLE 19

As the resol type phenolic resin solution, the following was employed:

Namely, 94 g of phenol, 70 g of nonylphenol, 137 g of 37% formalinaqueous solution and 5 g of 28% ammonia aqueous solution were fed into areaction vessel, and reacted with stirring at 95° C. for 5 hours. Aftercompletion of the reaction, the reaction product was dehydrated underreduced pressure and dehydration was stopped when the inner temperaturereached 90° C., followed by cooling and adding acetone to obtain a resoltype phenolic resin solution having a resin content of 40%.

Rubber (1) (10 g) was employed based on 100 g of the thus obtained resoltype phenolic resin solution.

The rubber (1) was completely dehydrated, dissolved in 10 g of ethylacetate and employed in the form of solution of rubber in ethyl acetate.

Namely, a solution of rubber in ethyl acetate, containing 10 g of rubber(1) was added to 100 g of the resol type phenolic resin solution toobtain a phenolic resin composition 19 having a resin content of about39.0%.

EXAMPLE 20

Rubber (2) (7 g) was employed based on 100 g of the above-mentionedresol type phenolic resin solution.

Epoxy group-containing rubber (2) was completely dehydrated, dissolvedin 10 g of ethyl acetate and employed in the form of solution of rubberin ethyl acetate.

Namely, a solution of rubber in ethyl acetate, containing 7 g of rubber(2) was added to 100 g of the above-mentioned resol type phenolic resinsolution to obtain a phenolic resin composition 20 having a resincontent of 38.0%.

EXAMPLE 21

Similarly, rubber solution (5) (8 g) was added to 100 g of theabove-mentioned resol type phenolic resin solution, to obtain a phenolicresin composition 21 having a resin content of about 40.7%.

EXAMPLE 22

Similarly, rubber (6) (4 g) was added to 100 g of the above-mentionedresol type phenolic resin solution, followed by stirring at roomtemperature for 60 minutes to obtain a phenolic resin composition 22having a resin content of about 42.3%.

EXAMPLE 23

Similarly, rubber solution (8) (12 g) was employed based on 100 g of theabove-mentioned resol type phenolic resin solution.

Rubber solution (8) was subjected to complete removal of solvent,dissolved in 10 g of ethyl acetate and employed in the form of solutionof rubber in ethyl acetate.

Namely, a solution of rubber in ethyl acetate, containing 12 g of rubbersolution (8) was added to 100 g of the resol type phenolic resinsolution to obtain a phenolic resin composition 23 having a resincontent of about 38.0%.

EXAMPLE 24

Rubber solution (9) (6 g) was added to 100 g of the above-mentionedresol type phenolic resin solution to obtain a phenolic resincomposition 24 having a resin content of about 41.7%.

Employing the respective phenolic resin compositions obtained inExamples 19 to 24, a cotton linter paper was impregnated therewith andthen dried to obtain a base having 45% by weight of resin adhered. Tensheets of this base were overlaid on a copper foil having an adhesiveadhered thereto, and they were subjected to contact bonding at 160° C.under a pressure of 100 Kg/cm² for 50 minutes to obtain a copper-lined,laminated sheet of 1.5 mm thick.

COMPARATIVE EXAMPLE 18

Employing the above-mentioned resol type phenolic resin solution, acotton linter paper was impregnated therewith and then dried to obtain abase having 45% by weight of resin adhered. Ten sheets of this base wereoverlaid on a copper foil having an adhesive adhered thereto, and theywere subjected to contact bonding at 160° C., under a pressure of 100Kg/cm² for 50 minutes to obtain a copper-lined, laminated sheet of 1.5mm thick.

The physical properties of the copper-lined, laminated sheets obtainedabove are shown in Table 5.

                  TABLE 5                                                         ______________________________________                                                                    Specific volume                                                  Punching proces-                                                                           resistance.sub.(Ω-cm),                                     sability, room                                                                             normal condition,                                 Laminated sheet                                                                              temperature *1                                                                             C-90/20/65 *2                                     ______________________________________                                        According to Example 19                                                                      70-80        10.sup.10 -10.sup.11                              (phenolic resin composition                                                   19)                                                                           According to Example 20                                                                      70-80        10.sup.10 -10.sup.11                              (phenolic resin composition                                                   20)                                                                           According to Example 21                                                                      80-90        10.sup.10 -10.sup.11                              (phenolic resin composition                                                   21)                                                                           According to Example 22                                                                      80-90        10.sup.10 -10.sup.11                              (phenolic resin composition                                                   22)                                                                           According to Example 23                                                                      70-80        10.sup.10 -10.sup.11                              (phenolic resin composition                                                   23)                                                                           According to Example 24                                                                      80-90        10.sup.10 -10.sup.11                              (phenolic resin composition                                                   24)                                                                           According to Comparative                                                                     20-30        10.sup.10 -10.sup.11                              example 18                                                                    (resol type phenolic resin                                                    solution)                                                                     ______________________________________                                         *1 According to ASTM D 61744                                                  *2 According to JlS C6481                                                

As shown from Table 5, the phenolic resin compositions of the presentinvention exhibit superior punching processability when they are made upinto laminated sheets.

EXAMPLE 25

A poly-p-vinylphenyl having a weight average molecular weight of about6,000 (hereinafter abbreviated to phenolic polymer A) (Maruzen M,tradename of a product manufactured by Maruzen Sekiyu K.K., Japan) wasemployed.

Namely, 150 g of rubber(1) were added to 500 g of the phenolic polymerA, and water was distilled off by vacuum drying and removed to theoutside of the system. The resulting material was melt-kneaded by meansof heated rolls at 160° C., for 15 minutes to obtain a phenolic resincomposition 25.

EXAMPLE 26

Similarly, 100 g of rubber solution (3) were added to 500 g of thephenolic polymer A, and solvent was distilled off by vacuum drying andremoved to the outside of the system. The resulting material wasmelt-kneaded by means of heated rolls at 160° C. for 15 minutes toobtain a phenolic resin composition 26.

EXAMPLE 27

Similarly, 50 g of rubber (4) were added to 500 g of the phenolicpolymer A, and the resulting material was melt-kneaded at 160° C. for 15minutes to obtain a phenolic resin composition 27.

EXAMPLE 28

Similarly, 100 g of rubber solution (5) were added to 500 g of thephenolic polymer A, and solvent was distilled off by vacuum drying andremoved to the outside of the system. The resulting material wasmelt-kneaded by heated rolls at 160° C. for 15 minutes to obtain aphenolic resin composition 28.

EXAMPLE 29

Similarly, 200 g of rubber solution (5) were added to 500 g of thephenolic polymer A, and solvent was distilled off by vacuum drying andremoved to the outside of the system. The resulting material wasmelt-kneaded by means of heated rolls at 160° C. for 15 minutes toobtain a phenolic resin composition 29.

EXAMPLE 30

Similarly, 200 g of rubber solution (7) were added to 500 g of thephenolic polymer A, and solvent was distilled off by vacuum drying andremoved to the outside of the system. The resulting material wasmelt-kneaded by means of heated rolls at 160° C. for 15 minutes toobtain a phenolic resin composition 30.

EXAMPLE 31

Similarly, 50 g of rubber (10) were added to 500 g of the phenolicpolymer A, and the resulting material was melt-kneaded by means ofheated rolls at 160° C. for 15 minutes to obtain a phenolic resincomposition 31.

Employing the respective phenolic resin compositions obtained inExamples 25 to 31, together with other materials according to thefollowing formulation, molding materials were prepared:

    ______________________________________                                        Phenolic resin composition                                                                          66     parts by weight                                  Bisphenol A type epoxy resin                                                                        100    parts by weight                                  (Epikote 828, tradename of                                                    product made by Shell Chemical                                                Co., epoxy equivalent: 190)                                                   Boron trifluoride-monoethylamine                                                                    1      parts by weight                                  complex (made by Shell Chemical                                               Co., BF.sub.3 : 400)                                                          ______________________________________                                    

The above-mentioned blends were melt-kneaded by means of heated rolls at80° C. for 8 minutes, and then molded under the conditions of 170° C.,10 minutes, 100 Kg/cm², and the resulting molded products weremaintained at 180° C., for 10 hours to effect post cure.

COMPARATIVE EXAMPLE 19

A molded product was prepared in the same manner as mentioned aboveexcept that phenolic polymer A was employed in place of phenolic resincompositions.

The physical properties of the molded products obtained above are shownin Table 6.

                  TABLE 6                                                         ______________________________________                                                     Impact strength, kg-cm*.sup.1                                                                       normal                                     Molded product -40° C.                                                                           -20° C.                                                                         condition                                  ______________________________________                                        According to Example 25                                                                      30         50       50                                         (phenolic resin composi-                                                      tion 25)                                                                      According to Example 26                                                                      20         40       50                                         (phenolic resin composi-                                                      tion 26)                                                                      According to Example 27                                                                      20         40       50                                         (phenolic resin composi-                                                      tion 27)                                                                      Acording to Example 28                                                                       40         50       50                                         (phenolic resin composi-                                                      tion 28)                                                                      According to Example 29                                                                      50         50       60                                         (phenolic resin composi-                                                      tion 29)                                                                      According to Example 30                                                                      30         40       40                                         (phenolic rcsin composi-                                                      tion 30)                                                                      According to Example 31                                                                      30         40       40                                         (phenolic resin composi-                                                      tion 31)                                                                      According to Comparative                                                                     10 or      10       30                                         example 19 (phenolic                                                                         less                                                           polymer A)                                                                    ______________________________________                                         *.sup.1 A wedge of 1/2 inch in diameter was applied to a molded product o     50 × 50 × 5 mm, and a weight of 1 Kg was dropped from an          optional height to observe a height (cm) at which crack occurred in the       molded product.                                                          

As seen from Table 6, a notable improvement in the impact strength notonly under normal condition but also at low temperatures is observedwith phenolic polymer A according to the method of the presentinvention.

EXAMPLE 32

Acrylonitrile (270 g), styrene (630 g), p-isopropenylphenol (100 g),ethyl acetate (250 g) and 2,2'-azobis(2,4-dimethylvaleronitrile (5 g)were fed and polymerized at 60° C. for 4 hours, followed by furtheradding ethyl acetate (250 g) and 2,2'-azobis(2,4-dimethylvaleronitrile)(5 g) and further polymerization at 60° C. for 4 hours. Solvent was thenremoved under reduced pressure to obtain a copolymer ofisopropenylphenol (hereinafter abbreviated to phenolic polymer B). Theviscosity of 5% solution of phenolic polymer B in ethyl acetate, at 25°C., was 1.75 cps.

Rubber (1) (150 g) was added to 500 g of phenolic polymer B, and waterwas distilled off by vacuum drying and removed to the outside of thesystem. The resulting material was melt-kneaded by means of heated rollsat 160° C. for 15 minutes to obtain a phenolic resin composition 32.

EXAMPLE 33

Similarly, 75 g of rubber solution (5) were added to 500 g of thephenolic polymer B, and solvent was distilled off by vacuum drying andremoved to the outside of the system. The resulting material wasmelt-kneaded by means of heated rolls at 160° C. for 15 minutes toobtain a phenolic resin composition 33.

EXAMPLE 34

Similarly, 150 g of rubber solution (5) were added to 500 g of thephenolic polymer B, and solvent was distilled off by vacuum drying andremoved to the outside of the system. The resulting material wasmelt-kneaded by means of heated rolls at 160° C. for 15 minutes toobtain a phenolic resin composition 34.

EXAMPLE 35

Similarly, 50 g of rubber (6) were added to 500 g of the phenolicpolymer B, and the resulting material was melt-kneaded by means ofheated rolls at 160° C. for 15 minutes to obtain a phenolic resincomposition 35.

EXAMPLE 36

Similarly, 200 g of rubber solution (7) were added to 500 g of thephenolic polymer B, and solvent was distilled off by vacuum drying andremoved to the outside of the system. The resulting material wasmelt-kneaded by means of heated rolls at 160° C. for 15 minutes toobtain a phenolic resin composition 36.

EXAMPLE 37

Similarly, 50 g of rubber (10) were added to 500 g of the phenolicpolymer B, and the resulting material was melt-kneaded by means ofheated rolls at 160° C. for 15 minutes to obtain a phenolic resincomposition 37.

Employing the respective phenolic resin compositions obtained inExamples 32 to 37, together with other materials according to thefollowing formulation, molding materials were prepared:

    ______________________________________                                        Phenolic resin composition                                                                        100    parts by weight                                    Hexamethylenetetramine                                                                            5      parts by weight                                    Magnesium stearate  0.5    parts by weight                                    ______________________________________                                    

The above blends were kneaded by means of heated rolls at 150° C. for 3minutes and then molded under the conditions of 230° C., 5 minutes, 100Kg/cm² to obtain molded products.

COMPARATIVE EXAMPLE 20

Molded products were prepared in the same manner as mentioned aboveexcept that phenolic polymer B was employed in place of the phenolicresin compositions.

The physical properties of the molded products obtained above are shownin Table 7.

                  TABLE 7                                                         ______________________________________                                                     Impact strength, Kg-cm*.sup.1                                                                       normal                                     Molded Product -40° C.                                                                           -20° C.                                                                         condition                                  ______________________________________                                        According to Example 32                                                                      20         30       40                                         (phenolic resin composi-                                                      tion 32)                                                                      According to Example 33                                                                      30         40       40                                         (phenolic resin composi-                                                      tion 33)                                                                      According to Example 34                                                                      40         50       50                                         (phenolic resin composi-                                                      tion 34)                                                                      According to Example 35                                                                      30         40       40                                         (phenolic resin composi-                                                      tion 35)                                                                      According to Example 36                                                                      20         30       40                                         (phenolic resin composi-                                                      tion 36)                                                                      According to Example 37                                                                      30         40       40                                         (phenolic resin composi-                                                      tion 37)                                                                      According to Comparative                                                                     10 or      10       20                                         example 20 (phenolic                                                                         less                                                           polymer B)                                                                    ______________________________________                                         *.sup.1 A wedge of 1/2 inch in diameter was applied to a molded product o     50 × 50 × 5 mm, and a weight of 1 Kg was dropped from an          optional height to observe a height (cm) at which crack occurred in the       molded product.                                                          

As seen from Table 7, a notable improvement in the impact strength notonly under normal condition but also at low temperatures is observedwith phenolic polymer B according to the method of the presentinvention.

EXAMPLE 38

As a polymer of phenol and p-xylylene dialkyl ether, a polymericsubstance having a softening point of 85° to 105° C. (Xylok 225,tradename of a product made by Albright & Wilson Ltd.) (hereinafterabbreviated to phenolic polymer C) was employed.

Rubber (1) (150 g) were added to 500 g of the phenolic polymer C, andwater was distilled off by vacuum drying and removed to the outside ofthe system. The resulting material was melt-kneaded by means of heatedrolls at 160° C. for 15 hours to obtain a phenolic resin composition 38.

EXAMPLE 39

Similarly, 75 g of rubber solution (5) were added to 500 g of thephenolic polymer C, and solvent was distilled off by vacuum drying andremoved to the outside of the system. The resulting material wasmelt-kneaded by means of heated rolls at 160° C. for 15 minutes toobtain a phenolic resin composition 39.

EXAMPLE 40

Similarly, 150 g of rubber solution (5) were added to 500 g of thephenolic polymer C, and solvent was distilled off by vacuum drying andremoved to the outside of the system. The resulting material wasmelt-kneaded by means of heated rolls at 160° C. for 15 minutes toobtain a phenolic resin composition 40.

EXAMPLE 41

Similarly, 50 g of rubber (6) were added to 500 g of the phenolicpolymer C, and the resulting material was melt-kneaded by means ofheated rolls at 160° C. for 15 minutes to obtain a phenolic resincomposition 41.

EXAMPLE 42

Similarly, 200 g of rubber solution (7) were added to 500 g of thephenolic polymer C, and solvent was distilled off by vacuum drying andremoved to the outside of the system. The resulting material wasmelt-kneaded by heated rolls at 160° C. for 15 minutes to obtain aphenolic resin composition 42.

EXAMPLE 43

Similarly, 50 g of rubber (10) were added to 500 g of the phenolicpolymer C, and the resulting material was melt-kneaded by means ofheated rolls at 160° C. for 15 minutes to obtain a phenolic resincomposition 43.

Employing the respective phenolic resin compositions obtained in Example38 to 43, together with other materials according to the followingformulation, molding materials were prepared:

    ______________________________________                                        Phenolic resin composition                                                                        100    parts by weight                                    Hexamethylenetetramine                                                                            12     parts by weight                                    Magnesium stearate  2      parts by weight                                    Asbestos powder     60     parts by weight                                    ______________________________________                                    

The above blends were kneaded by means of heated rolls at 105° C. for 5minutes, and then molded under the conditions of 170° C., 5 minutes, 100Kg/cm² to obtain molded products, which were then maintained at 180° C.for 10 hours to effect post-cure.

COMPARATIVE EXAMPLE 21

A molded product was prepared in the same manner as mentioned aboveexcept that phenolic polymer C was employed in place of the phenolicresin compositions.

The physical properties of the molded products obtained above are shownin Table 8.

                  TABLE 8                                                         ______________________________________                                                     Impact strength, Kg-cm*.sup.1                                                                       normal                                     Molded product -40° C.                                                                           -20° C.                                                                         condition                                  ______________________________________                                        According to Example 38                                                                      20         30       30                                         (phenolic resin composi-                                                      tion 38)                                                                      According to Example 39                                                                      20         30       30                                         (phenolic resin composi-                                                      tion 39)                                                                      According to Example 40                                                                      30         40       40                                         (phenolic resin composi-                                                      tion 40)                                                                      According to Example 41                                                                      20         30       30                                         (phenolic resin composi-                                                      tion 41)                                                                      According to Example 42                                                                      20         20       30                                         (phenolic resin composi-                                                      tion 42)                                                                      According to Example 43                                                                      20         30       30                                         (phenolic resin composi-                                                      tion 43)                                                                      According to Comparative                                                                     10 or      10       20                                         example 21 (phenolic                                                                         less                                                           polymer C)                                                                    ______________________________________                                         *.sup.1 A wedge of 1/2 inch in diameter was applied to a molded product o     50 × 50 × 5 mm, and a weight of 1 Kg was dropped from an          optional height to observe a height (cm) at which crack occurred in the       molded product.                                                          

As seen from Table 8, a notable improvement in the impact strength notonly under normal condition but also at low temperatures is observedwith phenolic polymer C according to method of the present invention.

EXAMPLE 44

Employing the phenolic resin composition obtained in Example 9, togetherwith other materials according to the following formulation, a moldingmaterial was prepared:

    ______________________________________                                        Phenolic resin composition                                                                        100    parts by weight                                    Hexamethylenetetramine                                                                            12     parts by weight                                    Magnesium stearate  1      parts by weight                                    ______________________________________                                    

The blend was kneaded by means of heated rolls at 105° C. for 3 minutesto obtain a molding powder. With 20 parts by weight of this moldingpowder were mixed 80 parts by weight of Hedman Cathionic fiber (made byHedmannine's Limited., Canada) and 10 parts by weight of methanol. Theywere molded under the conditions of 170° C., 20 minutes, 100 Kg/cm² toobtain a molded product, which was further maintained at 175° C. for 10hours to effect post-cure.

COMPARATIVE EXAMPLE 22

A molded product was prepared in the same manner as mentioned above,except that a commercially available nitrile butadiene rubber (Hica1411, tradename of a product made by Nihon Geon Co. Japan; acrylonitrilecontent, 41% by weight).

Hot hardness of molded products obtained in Example 44 and ComparativeExample 22 are shown in FIG. 1.

As seen from FIG. 1, the molded product prepared employing the phenolicresin composition of the present invention is less in the proportion ofreduction in the surface hardness at high temperatures than that in thecase of conventional composition, and hence is suitable as binders suchas brake linings, etc.

What is claimed is:
 1. Phenolic resin compositions for moldingcomprising 100 parts by weight of a polymeric substance having aphenolic OH group selected from the group consisting a phenolic resinand a phenolic polymer and 1 to 100 parts by weight of a rubbercontaining an epoxy group in its molecule and having an epoxy equivalentof 500 to 30,000 said rubber containing an epoxy group being an acrylicpolymer and having a glass transition temperature of 25° C. or lower. 2.Phenolic resin compositions according to claim 1 wherein said polymericsubstance having a phenolic OH group is a phenolic resin selected fromthe group consisting of novolak type phenolic resins, novolak typephenolic resins having a high content of ortho bond and resol typephenolic resins.
 3. Phenolic resin compositions according to claim 1wherein said polymeric substance having a phenolic OH group is aphenolic polymer selected from the group consisting of alkenylphenolpolymers, copolymers of an alkenylphenol with another polymerizablemonomer, copolymers of a phenolic compound with a p-xylylene dihalideand copolymers of a phenolic compound with a p-xylylene dialkyl ether.4. Phenolic resin compositions according to claim 1 wherein saidpolymeric substance having a phenolic OH group is a phenolic resin. 5.Phenolic resin compositions according to claim 1 wherein said polymericsubstance having a phenolic OH group is a phenolic polymer.
 6. Phenolicresin compositions for molding obtained by melt-mixing 100 parts byweight of a phenolic resin with 1 to 100 parts by weight of a rubberhaving an epoxy group in its molecule and having an epoxy equivalent of500 to 30,000, said rubber having an epoxy group being an acrylicpolymer and having a glass transition temperature of 25° C. or lower.